1. Field of the Invention
This invention relates to cleaning machines such as vacuum cleaning machines and water extraction machines and, more particularly, to a water extraction machine having an improved switch for controlling the supply of electricity to a power foot.
2. Description of Related Art
Carpeting and other floor surfaces have long been cleaned by using a vacuum cleaning machine which applies suction through a nozzle to the floor surface. Experience has shown that agitating the carpet strands with a rotating brush or beater bar improves the cleaning performance of the vacuum cleaning machine. Agitation members are typically mounted in the nozzle of an upright vacuum or the foot of a canister vacuum. The agitation member is usually driven by an agitation motor mounted adjacent the agitation member and interconnected thereto by a belt. The traditional power foot has an electric motor mounted in the power foot which is linked to the rotating agitation member by a belt or other interconnection.
Water extraction or deep cleaning is another process which can be used to clean carpeting or other floor surfaces. In this process, cleaning solution is sprayed onto the carpet surface and is then removed by an appropriate source of suction. The water extraction process can be more effective at removing dirt and dust from the carpet or floor surface than traditional vacuuming or vacuuming with an agitation member.
The cleaning performance of water extraction machines can be improved similar to the performance of vacuum cleaning machines through the incorporation of a rotating agitation member. The rotating agitation member helps to drive the cleaning solution deeper into the carpeting and also acts as a liquid media to aid in removing dirt and dust trapped in the carpet.
One significant problem with using a power foot with a water extraction machine is to provide an adequate separable connection between the power foot and the extraction machine. Such a device intended for use by consumers must pass several safety tests in order to receive certain consumer certifications. For example, Underwriter's Laboratories, Inc. ("UL") requires that all or a portion of the electrical power interconnection between the water extraction machine housing and the power foot be immersible in water and yet not result in electrical shock to the user. Such rigorous testing requirements presents a considerable challenge in engineering a suitable interconnection and electrical circuit between the power foot and the housing of a water extraction machine.
One mechanism which is designed to provide a waterproof electrical connector for an electrified vacuum hose is disclosed in U.S. Pat. No. 4,316,304 issued Feb. 23, 1982 to Parise et al. This connection assembly comprises a cylindrical plunger mounted within a plastic cuff. The cuff receives the male prongs of an electrical plug and completes the electrical circuit by moving the plunger within the cuff until it abuts an electrical contact mounted at the other end of the cuff. The plunger is biased such that when the male plug is withdrawn from the cuff, there is an open electrical circuit between the machine housing and the power foot.